Organotin compounds, particularly useful as stabilizers for halogen containing polymers, are well-known in the art. These organotin compounds can provide stabilization of such polymers when used alone or in combination with various compounds. For example, U.S. Pat. No. 3,503,924 to M. W. Pollock discloses stabilizers for polyvinyl chloride resins which are mixtures containing a diorganotin mercaptide and a minor amount of an alpha-mercapto acid. Pollock also discloses, in U.S. Pat. No. 3,507,827, stabilizer combinations for decreasing early discoloration of polyvinyl chloride resins which contain (1) a dialkyl, dicycloalkyl or alkylcycloalkyl tin mercapto carboxylic acid ester, and (2) an alpha- or beta-mercapto acid having at least three carbon atoms, or an alpha- or beta-mercapto alcohol having at least two carbon atoms.